Fluorescent agents from diamino stilbene



msimm atenteci Nov. 3 195 3 UNITED STATES PATENT OFFICE FLUORESCENT AGENTS FROM DIAMINO STILBENE William Eldred Wallace, Belvidere, N. J., and William Wilson Williams, Easton, Pa., assignors to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application August 10, 1950, Serial No. 178,745

2 Claims.

Formula I Y X wherein the group represents NH2 or the residue of a primary or secondary amine and Z represents the group COOM or $03M in which M represents hydrogen or a cation, usually alkali metal (1. e. sodium or potassium) or ammonium, alkylol amino, etc., or alkaline earth metal such as barium or calcium.

These novel compounds are readily prepared by first condensing a 4,4-diamino-stilbene sulfonic or carboxylic acid usually 4,4' diaminostilbene-2,2'-disulfonic acid (although other 4,4- diamino-stilbene acids such as 4,4'-diaminostilbene-3,3'-disulfonic acid, 4,4'-diaminostilbene- 2,2,6,6'-tetrasulfonic acid, 4,4'-diaminostilbene- 2,2'dicarboxylic acid, or 4,4'-diaminostilbene- 3,3'-dicarboxylic acid may be used if desired) with cyanuric chloride; 2 molar proportions of cyanuric chloride (or bromide) being employed for each molar proportion of 4,4'-diamino-stilbene-2,2'-disulfonic acid. The thus obtained primary condensation product is then further condensed with 2 molar proportions of an aminopyridine preferably 2-amino-pyridine (although other amino pyridines such as 3-aminopyridine 2 and 4-amino-pyridine or alkyl substituted aminopyridines such as 2methyl-6-aminopyridine may be used if desired) whereby there is obtained a novel intermediate product having the following formula:

wherein X stands for chlorine or bromine and Z is as defined above.

This novel intermediate product is then finally condensed with 2 molecular proportions of ammonia or a primary or secondary amine in order to obtain the novel products of the present invention.

These condensations may be carried out by procedures commonly employed in the art for efiecting such condensations. In order to fully illustrate the preparation of compounds of present invention the following detailed illustrations of the preparation of the novel intermediate of the present invention and of specific fluorescent agents embodied therein are given. The parts are by weight.

Preparation of intermediate.37 parts of cyanuric chloride are dissolved in parts of acetone and poured into a mixture of ice and water. During the suspension in the ice water the temperature of the aqueous suspension should not rise above 570. 37 parts of 4,4- diaminostilbene-2,2-disulfonic acid are dissolved in parts of water with the addition of enough sodium carbonate to give a neutral solution. This solution is then added slowly to the cyanuric chloride suspension in ice water and at the same time a solution of sodium carbonate is slowly added in order to keep the mixture from becoming too acid. During this addition and consequent condensation the temperature should not rise above C. The condensation of the cyanuric chloride with the diamino-stilbene-disulfonic acid is complete when a sample of the reaction mixture which has been acidified and treated with sodium nitrite does not develop color when treated with an alkaline solution of "R salt.

When this condensation is complete a solution of 9.4 parts of Z-amino-pyridine is added to the thus obtained product and immediately afterwards a solution of 160 parts of anhydrous sodium acetate in 400 parts of water is added. The thus obtained mixture is allowed to warm to room temperature and may be heated to to C. if necessary to completeithe condensation. Thus there is obtained the novel intermediate of the Formula II above (in which X is chlorine and Z is in 2 position and represents -SO3H in the form of the free acid.

This product is itself a fluorescent agent but" does not have outstanding properties as such and is therefore preferably further condensed'with ammonia or a primary or'secondary amine: to produce the improved fluorescent agentsof this invention. This condensation is readily eflfected by adding approximately 2 mols of ammonia or a primary or secondary amine to the mixture of a novel intermediate product obtained-as described above, without purification. There is also added a sufiicient amount of alkali such as sodium carbonate. in order to increase the .pH of-the solution to 7.5 to 8 and the mixture is heated to'temperaturei'of about 90 C. until the condensation is complete. The novel products of the present invention may then be isolated in the usual manner.

Preparation of fluorescent agents.-In each of the following examples the novelintermediate product employed was prepared as described above and was used without purification or other treatment.

EXAMPLE I This material ista'n in color and moderatelysoluble in water but very slightly soluble in acetone, alcohol, ether, etc.

EXAMPLE n To the novel intermediate product obtained as above described there is added 27.9'parts of aniline and the pH is increased to 8.0 to 8.5 by the addition of sodium carbonate. solutionand the mixture slowly heated to' 90 C; and maintained at this temperature for 3 hours. There is obtained-on cooling of'the reaction'mixture and isolation in the usual manner a compound corresponding to the formula:

N CNH CH:

| OsNa EXAMPLE I11 To the novel intermediate product obtained "as -'above 'described'there is added 24 parts of morpholine and the pH is increased to 8.0 to 8.5 by the addition of sodium carbonate solution and 'the mixture slowly heated to C. and maintainedat'thistemperature for 3 hours.

There is=obtained on cooling of the reaction mixture and isolation in the usual manner a compound corresponding to the formula:

To the: novel intermediate productobtainedas above-described there: is added 36:9; parts 011-panisidineand thepH-lisincteasedto 8042a 85, by

the addition of sodium carbonate solution and. the mixture slowly heated to 90 C. and maintained at this temperature for 3 hours. There is obtained on cooling of the reaction mixture and isolation in the usual manner a compound corresponding to the formula:

To the novel intermediate product obtained as above described there is added 36.3 parts of N-ethyl-aniline and the pH is increased to 8.0 to 8.5 by the addition of sodium carbonate solution and the mixture slowly heated to 90 C. and maintained at this temperature for 3 hours. There is obtained on cooling of the reaction mixture and isolation in the usual manner a compound corresponding to the formula:

When the above materials are incorporated in discharge pastes and applied to fabrics in the usual manner, the whites thus obtained were noticeably whiter than those using ordinary discharge pastes. When the materials are applied to fibers of cellulose, wool and nylon by methods well known in the art, the white appearance of the fabric was thereby much improved. When small amounts of these materials are added to soaps and synthetic detergents and the resulting mixture employed to wash fabrics, white materials thus washed are extraordinarily whiter in appearance and colored materials brighter than similar materials which are washed using ordinary soaps or detergents.

As examples of amines which may be condensed with the intermediate of Formula II above to produce valuable fluorescent agents of Formula I above in which the group Y X I will correspond to the amino radical of the paretc., also heterocyclic amines such as Z-aminothiazole, 2-aminobenzothiazole, Z-amino-pyrimldine etc., also cycloalkyl-amines such as cyclohexyl-amine, tetrahydronaphthyl-amine, etc., also alkaryl amines such as benzyl-amine etc. As example of secondary amines which may be used may be mentioned the secondary amines corresponding to any of the above primary amines in which an amino hydrogen has been replaced by an alkyl, aryl, or heterocyclic group, for instance-dialkyl amines such as dimethyl-, diethyl-, methyl ethyl-, dibutyl-, diamy1-, methyl-butyl-, methylcyclohexyl-amines, also N- alkyl aryl amines such as N methyl-, N-ethyl-. or N butyl-anilines, -anisidines, -naphthylamines, -amino-thiazoles, -aminopyridines etc., also such heterocyclic secondary amines as carbazole, thiomorpholine, pyrrole, pyrrolidine, indole etc.

A number of derivatives of the type indicated above at 4,4='-bis-[4-amino 6 (2 aminopyridine)-2-5-triazinylamino] 2,2 stilbenedisulfonic acid and its salts have been prepared and it has been found that the compounds of the present invention which in the 6 position of the triazyl ring contain a 2 amino-pyridine substituent and in 4 position of the tri'azyl ring contain an amino substituent are desirable fluorescent agents and are superior to known fluorescent agents of the same general type; i. e. which contain no amino pyridine substituent in the triazyl ring but instead contain amino, hydroxy substituents and the like. It is therefore believed that the nature of the amino substituent in 4 position is not highly critical and that substantially any primary or secondary amine, as well as ammonia, may be condensed with the novel intermediate of the present invention to produce valuable fluorescent agents. It is, however, preferable that the amino substituent in 4 position in the triazinyl ring contain no groups such as free amino or hydroxy groups etc. which as a usual rule have an adverse effect on the light and chlorine fastness of the fluorescent agents.

It will be apparent that in the foregoing examples the novel products of the present invention were obtained in the form of their sodium salts. However, the potassium salts have substantially similar properties and it will be apparent that the potassium salts will be obtained by using potassium carbonate and acetate in place of sodium carbonate and acetate as the alkaline agents for the condensations in the synthesis of these materials. The free acids may be obtained by acidification of the sodium or potassium salt while other salts such as the ammonium or alkylol amine salts may be obtained by neutralization of the free acids. Where spirit soluble products are desired, for instance, in brightening of lacquers etc. the higher alkyl or cycloalkyl-amine salts of the free acids such as the cyclohexyl-amine salts of the free acids may be produced by methods known in the art. The alkaline earth metal salts such as the barium and calcium salts which may be obtained from the free acid or by double decomposition of the sodium or potassium salts have been found. to: be useful for" the. brightening: of: photographic prints etc.

' Inaddition to the: specifics. fluorescent agents; described above; it hasbeen found; that the-novel: products represented by the: generalv Formula. I. abovev and which may be: obtained. by condens;- mg: the novel. intermediate: represented. by; Eur. mula II above. withv a. wide." variety: of primary and' secondary. amines are a1so.-Va1uableifiuo.-- rescent agents.

The novelrfluorescenti agents: of the: present: invention fluoresce under ultra-violet light. with: abluish fluorescence, and; since: they are: substantive to cellulosic materials; are: particularly valuable for incorporation: into.- soaps and'syn-r thetic detergents. suchnas alkylaryl sulfonatesi. higher. fatty. acid methyl-taurides,, non-ionic;'de.-= tergents: such as. the: polyglycolethers ct. aikyl; phenols. or; ofpartial; higher; fatty" acid. esters of. mannitol or: sorbitol; The: fabrics. washed with formulations of detergentscontaining; these: fluorescent agents appear much whiter: im the: case; of whites andmuch: brighter the: case: of: colors. than: fabrics. which. are washed with: ordinary soapslor detergents; illhesefiuorescentt agents may also be applied to fabrics by/separate treating: baths and-similar methods. and procedures well. known. in; the art- Theyare also useful. when incorporated; into. paper. or. other wrappingmaterials particularly cellulosic. wrapping: material. to. improve the whiteness: of such material, as well as to; protect the-contents from. the. action of ultra-violetlieht. They may also be. incorporated in-discharge pastes. whence by the. whites obtained upon: discharge are de.-= cideclly' whiter than'. those. discharges made in; the absenceof such: materials. They; may also. be used to.- bleach fabrics and. in suclr cases the. amount of bleachnecessary isamaterially-reducedz and= one-or more. steps. of the ncrmaLbleaching. operations may be eliminated.

' We "claim;

11. Eluorescentzbrighteningr agentszwhiclrinthe:

form of thei-ree: acid have: the; formula:

wherein W represents. a member of' the group consisting-of bromine and" chlorine,v diethanolamino-, anilino-',. N-ethy1anilino-, toluidino-, anisidino-, andm'orpholinm.

2. Fluorescent agents which in the form of the free acid have the formula WILLIAM ELDRED WALLACE. WILLIAM WILSON WILLIAMS.

No references cited; 

2. FLUORESCENT AGENTS WHICH IN THE FORM OF THE FREE ACID HAVE THE FORMULA 